Analogue eddy detecting apparatus and method for calibrating the same

The invention relates to a method for calibrating the initial sensitivity of the eddy current roll-flaw detecting apparatus and an eddy current roll-flaw detecting apparatus which can be calibrated by the method. The method comprises the following steps: a) detecting an artificial defect sample to obtain a first vector; b) generating an analogue artificial defect signal; c) adjusting the analogue artificial defect signal to make it equal the first vector; and d) inputting the analogue artificial defect signal into the eddy current roll-flaw detecting apparatus, and adjusting the eddy current roll-flaw detecting apparatus to enable it to give a warning, wherein steps a) and c) are both implemented by means of the impedance analyzing unit having the function of displaying the impedance vector built in the eddy current roll-flaw detecting apparatus. The eddy current roll-flaw detecting apparatus comprises an impedance analyzing unit having the function of displaying the impedance vector, a modulation analyzing circuit and a warning circuit.